Title

Author

Date of Award

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering - (M.S.)

Department

Biomedical Engineering

First Advisor

Tara L. Alvarez

Second Advisor

Bharat Biswal

Third Advisor

Mesut Sahin

Abstract

Every year, approximately 50 people per million of inhabitants are inflicted by Spinal Cord Injury (SCI). The long-term impairment of the SCI patients has led researchers to investigate different rehabilitation and treatment efforts that require careful observations to be made on reliable markers. Presently, a number of neuropsychological assessments are used for SCI rehabilitation and research purposes. However, there is a need for the discovery of sensitive biomarkers that can be used to characterize SCI. Altered functional connectivity in the brain has been observed in a number of neurological patient populations. Hence, it was hypothesized that such alterations in brain connectivity occurs after SCI as well. In this study, functional magnetic resonance imaging (fMRI) was used to study brain functions while at rest on 23 healthy control subjects and 38 SCI subjects. Based on the level of injury, SCI subjects were divided into two groups of paraplegic and tetraplegic subjects, respectively. Independent component analysis (ICA) was performed on the three groups of subjects as well as the on the study population in order to approximate underlying brain networks. Corresponding spatial independent components obtained from the three groups demonstrated difference in spatial maps. Analysis of variance revealed group differences among the three groups in three neural networks – default mode network, right lateralized fronto-lateral network, and sensorimotor network. In addition, correlations were found between the neuropsychological assessment scores and connectivity strength of the locations that demonstrated difference. The results from this study which is preliminary in nature demonstrated alterations in brain connectivity in SCI patients. Furthermore, this study may provide information that can be used as biomarkers for SCI patient population.